Method of determining the position of a supporting pin, and device for this

ABSTRACT

Method of determining the position of at least one supporting pin for supporting a side ( 15 ) of a substrate ( 14 ) in a component placement machine. In a first step of the method, the supporting side ( 15 ) of the substrate is made at least partly visible. Next at least one frame ( 25, 26, 27 ) is positioned opposite said supporting side ( 15 ) of the substrate, said frame comprising at least one fastening element for an auxiliary pin ( 28 ). Subsequently the auxiliary pin is arranged in the frame in a removable way in a position in which one end of the auxiliary pin makes contact with the supporting side of the substrate. The obtained position is used as the desired position of the supporting pin.

The invention relates to a method of determining the position of atleast one supporting pin for a side of a substrate to be supported in acomponent placement machine.

The invention also relates to a device suitable for implementing such amethod.

It is known per se to support a substrate by means of supporting pins ina component placement machine, inter alia for preventing sagging of thesubstrate during the placement of components on the substrate.

The supporting pins should bear on the side of the substrate to besupported such that on the one hand a sufficient support is obtained,while on the other hand it is prevented that the supporting pins bear oncomponents provided in an earlier phase on the side to be supported.

In a method known per se, a camera is used for observing the side of thesubstrate to be supported, whereupon the positions of the supportingpins are determined by a computer. Data have also been previously storedin the computer on the positions in which supporting pins can or cannotbe placed in the component placement machine.

It is a disadvantage of this method that the determination of thepositions of the supporting pins by means of a camera is comparativelycomplicated. In addition, it cannot be checked whether the supportingpins to be thus placed offer the substrate a sufficient support. Forthis purpose the supporting pins should first be provided in a componentplacement machine. Should the support be insufficient, then positionsare to be determined for additional supporting pins, which iscomparatively time-consuming. Furthermore, the component placementmachine cannot be used for the placement of components during testingwhether the desired support is offered by the supporting pins.

The invention has for its object to provide a method by which thedesired position of at least one supporting pin can be determined in acomparatively simple manner.

According to the invention, this object is achieved in the methodaccording to the invention in that

-   -   the substrate is rendered at least partly visible as regards its        side to be supported;    -   at least one frame is provided opposite the side to be        supported, which frame is provided with at least one fastening        element for an auxiliary pin;    -   the auxiliary pin is subsequently detachably provided in the        frame in a position in which an end of the auxiliary pin bears        on the side to be supported;    -   whereupon the position of the auxiliary pin is used as a desired        position for the supporting pin.

A frame may be provided by a user opposite the side of the substrate tobe supported at any time and in any location desired. The side to besupported here faces the user. Preferably, the lower side will be turnedso as to face upwards.

Then the user may provide at least one auxiliary pin in the frame on thebasis of his/her view of the supporting side. A plurality of auxiliarypins will mostly be used in practice. When an auxiliary pin is providedin the frame, the user will notice immediately if he/she trying toprovide the auxiliary pin in a location where a component is alreadypresent on the side of substrate to be supported. The user will also beable to realize a regular distribution of the auxiliary pins over thesubstrate in a simple manner.

After the auxiliary pins have been provided, the positions of theauxiliary pins are determined and are used as desired positions for thesupporting pins in the component placement machine.

The method according to the invention is comparatively simple and can beimplemented by comparatively low-level staff.

An embodiment of the method according to the invention is characterizedin that elements are provided opposite the side to be supported so as tobe located in positions corresponding to positions of obstacles tosupporting pins, which obstacles are present in the component placementmachine, before the auxiliary pin is provided in the frame.

It is prevented thereby that auxiliary pins are provided in the frame inlocations where obstacles are present in the component placementmachine, such as, for example, components of the component placementmachine.

A further embodiment of the method according to the invention ischaracterized in that the frame together with the auxiliary pins andwith the substrate is turned over after the placement of the auxiliarypins, after which the support provided by the auxiliary pins is checkedin that the substrate is pressed against the auxiliary pins.

It can thus be tested in a comparatively simple manner whether theauxiliary pins offer a sufficient support. If this is not the case,additional auxiliary pins can be provided in the frame until the desiredsupport has been obtained.

It is not until a sufficient support has been obtained that thepositions of the auxiliary pins are to be determined, whereupon they maybe used as positions for the supporting pins in the component placementmachine. It need not be tested anymore in the component placementmachine after that whether the substrate is sufficiently supported,because this has already been verified by means of the auxiliary pins.

A yet further embodiment of the method according to the invention ischaracterized in that the auxiliary pins are positioned together withthe frame in the component placement machine, during which the auxiliarypins act as the supporting pins.

The positions of the auxiliary pins are determined implicitly only inthis manner, because the desired positions of the auxiliary pins actingas the supporting pins are immediately obtained through the placement ofthe frame in the component placement machine.

The invention also relates to a device suitable for implementing themethod, which device is characterized in that the device is providedwith a holder for the substrate and with a frame which is provided withat least one fastening element for an auxiliary pin.

Auxiliary pins can be provided opposite the side of a substrate to besupported in a simple manner by means of such a device, whereupon thepositions of these auxiliary pins can be determined.

The invention will be explained in more detail below with reference tothe drawings, in which:

FIG. 1 is a perspective view of a first embodiment of a device accordingto the invention,

FIG. 2 shows a lower side of the device of FIG. 1,

FIG. 3 is a cross-sectional view taken on the line III-III of the deviceof FIG. 2,

FIG. 4 shows the device of FIG. 1 provided with stop pins,

FIG. 5 shows the device of FIG. 1 after the device has been turned over,

FIGS. 6 to 8 are a perspective view, a plan view, and a cross-section ofthe device of FIG. 5, respectively, in which a number of auxiliary pinshave been provided in the frame,

FIG. 9 shows an alternative embodiment of the device of FIG. 5, with theframe being provided with a transparent plate,

FIG. 10 shows an alternative embodiment of the device shown in FIG. 5,with the frame being provided with a steel plate,

FIG. 11 shows various embodiments of auxiliary pins in side elevation,

FIG. 12 shows the closing of the device of FIG. 5,

FIG. 13 shows an alternative embodiment for locking the auxiliary pinsin the frame,

FIG. 14 is a side elevation of a device for testing the support providedby the auxiliary pins,

FIG. 15 shows the device of FIG. 13, provided with a measuring device,

FIG. 16 is a side elevation of a device for determining the positions ofthe auxiliary pins by means of a camera, and

FIG. 17 shows the use of the frame provided with auxiliary pins for acomponent placement machine.

Corresponding components have been given the same reference numerals inthe Figures.

FIGS. 1 to 3 show a device 1 which is provided with two beams 2, 3 whichextend parallel to one another and which are provided with a number ofregularly spaced holes 4 at the up sides. The beams 2, 3 areinterconnected by crossbeams 5, 6, 7 extending transversely to the beams2, 3. The device is further provided with a lid 9 connected to the beams2, 3 with hinging possibility about a shaft 8. The crossbeam 7 isprovided with two elements 9, 10 which correspond to obstacles presentin a component placement machine (not shown). The elements 10, 11 areprovided with centering pins 12, 13. In the device shown in FIGS. 1 to3, a substrate 14 is positioned such that the substrate 14 lies withpositioning holes present in the substrate 14 over the positioning pins12, 13. The beams and crossbeams here form a holder for the substrate.The side of the substrate 14 facing upwards in FIG. 1 forms the sidewhich is yet to be provided with components in the component placementmachine. The side of the substrate 14 not visible in FIG. 1 forms theside to be supported in the component placement machine. This side 15 tobe supported is visible in FIGS. 2 and 3.

FIG. 4 shows an alternative embodiment of a device 21 according to theinvention which is provided with an element 22 on which stop pins 23 forthe substrate are fastened. The element 22 and the stop pins 23correspond to an object present in the component placement machine, towhich object stop pins are fastened.

FIG. 5 shows the device 1 of FIG. 1, the side facing upwards in FIG. 1now facing downwards. To prevent the substrate 14 from dropping from thedevice 1, the substrate 14 is locked previous to turning over in thedevice 1. The substrate 14 is locked in the device 1 between thecrossbeam 5 fixedly connected to the device 1 and the crossbeam 6 whichcan be detachably clamped in the beams 2, 3.

After the device 1 has been turned over, the lid 9 is pivoted about theshaft 8 in the direction indicated by arrow P1, so that the side 15 ofthe substrate 14 to be supported becomes accessible. As is visible inFIG. 5, the beams 2, 3 are also provided with holes 4 at the sidevisible now. As is also visible in FIG. 5, the crossbeam 7 is alsoprovided with holes 24.

FIG. 6 shows the device of FIG. 5, where a frame built up from strips25, 26, 27 is detachably fastened to the beams 2, 3 and the crossbeam 7,respectively.

The fastening of the strips 25, 26, 27 to the beams 2, 3 and thecrossbeam 7 may be effected, for example, by means of pegs which areinserted through the strips 25, 26, 27 into the holes 4, 24.Alternative, preferably detachable fastening means are obviously alsopossible.

The strips 25, 26, 27 are provided with a, preferably regular, patternof holes through when auxiliary pins 28 can be passed. A user 28 pushessaid pins through the strips 25, 27 in those locations where the usersees no components placed on the side 15 to be supported. In addition,the user should ensure that the auxiliary pins 28 are regularlydistributed over the side 15 to be supported.

The elements 10, 11 prevent the user from placing auxiliary pins inpositions which will not be accessible to supporting pins subsequentlyin the component placement machine.

FIG. 9 shows an alternative embodiment of a device 31 according to theinvention in which, instead of strips 25 to 27, a transparent, forexample synthetic resin plate 32 is used, in which holes 33 areprovided. Auxiliary pins 28 can be passed through the holes 33, duringwhich the transparent plate safeguards a substantially unhampered viewof the side 15 of the substrate 14 to be supported.

FIG. 10 shows a further embodiment 41 according to the invention, wherethe frame is formed by a sturdy, robust metal plate 42 provided withholes 43.

FIG. 11 shows a holder 45 in which three different auxiliary pins 46,47, 48 are located. The auxiliary pins 46 to 48 each have a head 49which will bear on the frame.

The auxiliary pin 46 has a comparatively great diameter so as to supportthe substrate over a comparatively large surface area. The auxiliary pin47 has a comparatively small diameter which is suitable in particularfor supporting the substrate between two components present on thesubstrate.

The auxiliary pin 48 is provided with a comparatively thin needle ofcomparatively small diameter.

FIG. 12 shows the device of FIG. 9, where the lid 9 is pivoted from theopen position in the direction indicated by arrow P2 into the closedposition referenced 9′. The lid 9 is closed the moment the user hasprovided a number of supporting pins 28 which he/she deems sufficient.

FIG. 13 shows an alternative embodiment of a device 51 according to theinvention in which the lid 59 can be shifted in and opposed to adirection indicated by arrow P3, i.e. a direction parallel to the beams2, 3, instead of the lid 9 hinging about a shaft 8.

FIG. 14 shows a device 61 which is provided with a C-shaped portal 62 inwhich a measuring ahead 63 displaceable in a horizontal plane ispositioned. The measuring head 63 is further provided with a measuringprobe 64 which is displaceable in a vertical direction indicated byarrow P4. After the lid 9, 59 has been closed, the relevant deviceincluding the frame, the auxiliary pins, and the substrate is turnedover such that the substrate 14 lies with its side 15 to be supported onthe auxiliary pins 28.

The measuring probe 64 subsequently presses on the substrate 14 in anumber of locations, preferably in between the auxiliary pins 28, with apredetermined force, and the displacement of the substrate 14 invertical direction is measured. If this displacement is greater thandesired, additional auxiliary pins 28 will have to be provided in themanner described above. Then the support provided by the auxiliary pins28 can be tested again by means of the device 61.

FIG. 15 shows the device 51 of FIG. 13, in which the beam 3 and the lid59 are provided with rulers 70, 71. The positions of all auxiliary pins28 can be determined in a simple manner through displacement of the lid59 in the direction indicated by arrow P5. For this purpose, the lid 59is stopped each time at the center of an auxiliary pin 28. The X- andY-positions of the auxiliary pin 28 can then be read on the rulers 71and 70 at the arrows P6 and P7, respectively. Preferably, the rulers 70,71 are provided with graduations which directly correspond to system ofcoordinates in a component placement machine. If this is the case,supporting pins can be provided directly in these positions in thecomponent placement machine. The provision of supporting pins in acomponent placement machine is known per se and will accordingly not beexplained in any detail.

FIG. 16 shows a device 81 which is provided with a C-shaped portal 82and a camera 83 fastened thereto. The positions of the auxiliary pins 28with respect to the portal 82 and/or the frame 32 and/or the device 31can be determined by means of the camera 83. The positions determined bythe camera 83 should then be converted into positions for the supportingpins in the component placement machine.

FIG. 17 shows a device 91 in which a frame 92 is provided with pins 93which are detachably fixed relative to the frame 92 by means of a lid94.

After the desired support of the substrate 14 by the pins 93 has beentested by means of a device, for example a device as shown in FIG. 14,or manually, the fame 92, the auxiliary pins 93, and the plate 94 arejointly transferred to a component placement machine (see the right-handportion of FIG. 17), where the auxiliary pins, 93 will act as supportingpins.

1. A method of determining the position of at least one supporting pinfor a side of a substrate to be supported in a component placementmachine, characterized in that the substrate is rendered at least partlyvisible as regards its side to be supported; at least one frame isprovided opposite the side to be supported, which frame is provided withat least one fastening element for an auxiliary pin; the auxiliary pinis subsequently detachably provided in the frame in a position in whichan end of the auxiliary pin bears on the side to be supported; whereuponthe position of the auxiliary pin is used as a desired position for thesupporting pin.
 2. A method as claimed in claim 1, characterized in thatthe substrate faces upwards with its side to be supported at the momentwhen the auxiliary pin is provided.
 3. A method as claimed in claim 1,characterized in that elements are provided opposite the side to besupported so as to be located in positions corresponding to positions ofobstacles to supporting pins, which obstacles are present in thecomponent placement machine, before the auxiliary pin is provided in theframe.
 4. A method as claimed in claim 1, characterized in that theframe together with the auxiliary pins and with the substrate is turnedover after the placement of the auxiliary pins, after which the supportprovided by the auxiliary pins is checked in that the substrate ispressed against the auxiliary pins.
 5. A method as claimed in claim 1,characterized in that the auxiliary pins together with the frame arepositioned in the component placement machine, during which theauxiliary pins act as the supporting pins.
 6. A method as claimed inclaim 1, characterized in that the positions of the auxiliary pinsrelative to the frame are determined.
 7. A method as claimed in claim 1,characterized in that the positions of the auxiliary pins are determinedby means of a camera.
 8. A device suitable for implementing the methodas claimed in claim 1, characterized in that the device is provided witha holder for the substrate and with a frame which is provided with atleast one fastening element for an auxiliary pin.
 9. A device as claimedin claim 8, characterized in that the device is provided with elementswhich can be positioned in positions relative to the frame for blockingthe provision of auxiliary pins in these positions.
 10. A device asclaimed in claim 8, characterized in that the frame is provided with ameasuring device for determining the positions of the auxiliary pinsrelative to the frame.
 11. A device as claimed in claim 8, characterizedin that the device is provided with means for detachably locking theauxiliary pins relative to the frame.
 12. A device as claimed in claim11, characterized in that said means comprise a lid.
 13. A device asclaimed in claim 12, characterized in that the lid can be translatedwith respect to the frame.
 14. A device as claimed in claim 12,characterized in that the lid is hinged to the frame.
 15. A device asclaimed in claim 8, characterized in that the frame together with theauxiliary pins can be positioned in a component placement machine.
 16. Adevice as claimed in claim 8, characterized in that the frame isprovided with at least one strip which can be detachably coupled to theholder.
 17. A device as claimed in claim 8, characterized in that theframe is provided with a transparent plate comprising a pattern ofholes.
 18. A device as claimed in claim 8, characterized in that theframe is provided with a steel plate comprising a pattern of holes.